Load-limiting line support for a post insulator

ABSTRACT

A line support for a post insulator includes a support bracket secured to the post insulator and carrying a saddle forming a channel extending in the direction of the line. A pair of opposed pins extend into the channel of the saddle from opposite sidewalls to hold a line clamp in place in the channel, and a retainer loop extends over the channel above the line clamp. The pins are formed to shear for releasing the clamp from the saddle channel under stress somewhat less than the strength of the insulator so that extraordinary tension on the line shears the pins to release the clamp rather than breaking the insulator.

United States Patent Thomas A. Pinkham;

Carl D. Fiero, Le Roy, N.Y. 875,869

Nov. 12, 1969 Feb. 23, 1971 Interpace Corporation Parsippany, NJ.

lnventors App]. No. Filed Patented Assignee LOAD-LIMITING LINE SUPPORT FOR A POST INSULATOR [56] References Cited UNITED STATES PATENTS 1,871,336 8/1932 Miller et al. .6 248/64 FOREIGN PATENTS 989,127 5/1951 France 248/64 1,035,722 8/1958 Germany 174/169 Primary ExaminerLaramie E. Askin Attorney-Charles E. Baxley ABSTRACT: A line support for a post insulator includes a support bracket secured to the post insulator and carrying a saddle forming a channel extending in the direction of the line. A pair of opposed pins extend into the channel of the saddle from opposite sidewalls to hold a line clamp in place in the channel, and a retainer loop extends over the channel above the line clamp. The pins are formed to shear for releasing the clamp from the saddle channel under stress somewhat less than the strength of the insulator so that extraordinary tension on the line shears the pins to release the clamp rather than breaking the insulator.

PATENTED FEB23I97I 3566LO11 INVENTORS THOMAS A., PINKHAM CARL o. FIERO AT TORNEYS 1 LOAD-LIMITING LINE SUPPORT FOR A POST INSULATOR j Tl-IE lNVENTlVE IMPROVEMENT sulators experience a sudden large stress-from the imbalance,

and insulator breakage can cascade along the line to break a large number of insulators because of a single mishap. Various measures have been proposed to prevent this, and the invention provides an improved solution.

The general object of the inventionis to limit the load on post insulators to stresses less than the insulators strength so that extraordinary stress on the line will not break the insulator and will lessen cascading insulator failure. The invention also aims at accomplishing this by a simple, economical, reliable and efficient device.

SUMMARY OF THE INVENTION The inventive load-limiting line support includes a support bracket secured to a post insulator and carrying a saddle forming a channel extending in the direction of the line. The saddle curves substantially downward atea'ch end'to form upwardly inclined surfaces leading into the channel. A pair of opposed saddle to slide out of channel16. The shear strength of bolt ends 23 is preferably selectedto insure that bolt ends 23 shear off at a stress somewhat less than the breaking strength of insulator 10. When bolt ends 23 shear to release clamp 24 for downline travel toward the excessive stress, clamp 24 moves rapidly out of channel 16. The resilience of line oflen draws clamp 24 back into chamnei 16 on a rebound after the initial movement, and the inclined surfaces 19 are shaped to guide clamp 24 freely back into channel 16 on such rebound motion. Surfaces 19 and the surfaces of channel 16 are smooth and unobstructed for free motion of line 20 and clamp 24' back and forth through saddle 15 until the line stabilizes. Meanwhile, retainer loop 21 prevents line 20 from falling out of saddle l5.

Such an arrangement insures that insulator 10 does not break to drop line 20 and it prevents cascading insulator breakage from a line mishap. Thus, the invention fulfills its objects in asimple and efficient load-limiting line support for post insulators. g

Persons wishing to practice the invention should remember that other embodiments and variations can be adapted to particular circumstances. Even though one point of view is necespins extend intothe channel from-theopposite side walls of the saddle, and a line clamp is held in the channel by the pins. A retainer loop is secured to each side of the channel and extends above the line clamp, and .the'pins are fonned to shear for releasing the clamp from thesaddlelchannel under stress somewhat less than the insulator strength. Preferably, the pins comprise the ends of bolts securingthe retainer loop to the channel. DRAWlNGS I FIG. 1 is an elevational view of a preferred embodiment of the inventive line support as viewed'in the direction of the I lin'e;-and

viewed transversely to the line.

' DETAILED DESCRIPTION FIG. 2 is an elevational view of the line support of FIG. 1 as I its line end. The inventive support is also applicable to vertical post insulators or post insulators set at other angles. Support bracket 12 is made to fit trunnion cap 11 and is secured to cap 11 by keeper l3 and bolts 14. Bracket 12 carries a saddle 15 forming a channel 16 extending in the direction of line 20 between sidewalls l7. Saddle IShas downwardly extending lips 18 that curve substantially downward so that inclined surfaces 19 slope upward into channel 16 at each end of saddle 15. A retainer loop 21 is secured to each sidewall 17 of saddle l 5'by bolts 22. The ends 23 of bolts 22 extend into channel'l6 from each sidewall 17 to engage and support a line clamp 24 secured to line 20. Clamp 24- and line 20 are thus disposed in channel 16 and held against movement by the engagement with bolt ends 23.

if line 20 is subjected to severe stress approaching the breaking strength of insulator l0, bolt ends 23 are sheared off by line clamp 24, and clamp 24 and-line 20 are released from sarily chosen in describing and defining the invention, this should not inhibit broader or related embodiments going beyond the semantic orientation of .this application but falling within the spirit of the invention. For example, different retainer loops and support brackets can be adapted to particular insulator caps, and other shear arrangements are possible within the scope of the invention.

We claim:

l. A load-limiting line support for a support comprising:

a. a support bracket;

b. means for securing said support bracket to said post insulator;

c. a saddle carried by said support bracket;

d. said saddle being formed to define a channel extending in the direction of said line;

c. said saddle curving substantially downward at each end to form upwardly inclined surfaces leading into said channel;

f. a pair of opposed pins extending into said channel from opposite sidewalls thereof; I

g. a line clamp held immovably in said channel by said pins;

h. a retainer loop secured to each side of said channel and extending above said line clamp; and

i. said pins being formed to shear for releasing said clamp from said saddle channel under stress somewhat less than the strength of said insulator.

2. The support of claim 1 wherein said pins comprise the post insulator, said line ends of bolts securing said retainer loop to said saddle.

' for registry with'second bolt holes provided in the support bracket, each of said first and second bolt holes in registry provided with a bolt penetrating therethrough for securely mounting the support bracket on the trunnion cap. 

1. A load-limiting line support for a post insulator, said line support comprising: a. a support bracket; b. means for securing said support bracket to said post insulator; c. a saddle carried by said support bracket; d. said saddle being formed to define a channel extending in the direction of said line; e. said saddle curving substantially downward at each end to form upwardly inclined surfaces leading into said channel; f. a pair of opposed pins extending into said channel from opposite sidewalls thereof; g. a line clamp held immovably in said channel by said pins; h. a retainer loop secured to each side of said channel and extending above said line clamp; and i. said pins being formed to shear for releasing said clamp from said saddle channel under stress somewhat less than the strength of said insulator.
 2. The support of claim 1 wherein said pins comprise the ends of bolts securing said retainer loop to said saddle.
 3. The support of claim 2 wherein said post insulator includes an outer end, said means for securing said support bracket to said post insulator comprising a trunnion cap secured to said outer end and having a flange which projects transverse the line, a keeper snugly engaging said flange and provided with at least one first bolt hole on each side thereof for registry with second bolt holes provided in the support bracket, each of said first and second bolt holes in registry provided with a bolt penetrating therethrough for securely mounting the support bracket on the trunnion cap. 